题解 | #网购#

#include <stdio.h>

int main() {
    float value;
    
    int month,day;
    int a;
    scanf("%f %d %d %d",&value,&month,&day,&a);
    if(month == 11&&day == 11)
    {
        value = value*0.7-50*a;
    }
    if(month == 12&&day == 12)
    {
       value = value*0.8-50*a;
       
    }
    if(value<0)
    printf("0.00\n");
    else
     printf("%.2f\n",value);
    return 0;
}